Replaceable blade straight razors (also known as shavettes) give you the closeness of a straight and the convenience of a disposalable.
Many people loved the testosterone-inducing buzz of a "cut-throat" straight razor, but they don't love the honing and stropping needed to keep it in that way. The shavette razor allows you the best of both worlds. You can get the closeness and feedback that you get with a long, sharp blade, but you don't have the maintenance when you can simply switch out the blades with a new, fresh edge. Also, great for barbers who need a new, sanitary blade with each client.